UPDATE: We have another post (above) that links to the New York Times DealBook blog which quotes much larger numbers:

...It’s also worth remembering that Mr. Greenberg is also a major stakeholder in A.I.G. He has seen the value of his holdings plummet as A.I.G. shares have sunk. He holds about 39 million A.I.G. shares directly and an additional 243 million through his private equity firm, Starr International. The shares were worth about $15.8 billion at the beginning of this year, but just $1.3 billion as of Monday.